Whole-body Positron Emission Tomography (WBPET) Scan in All Patients of Breast Cancer: Is This the Way Forward?

Abstract

Objectives: Globally, breast cancer is the second most frequently diagnosed malignancy just behind lung cancer, accounting for over 2 million cases each year. It is the second most commonly diagnosed cancer worldwide and the most common malignancy among females in India. The role of whole-body positron emission tomography (WBPET) in all cases of breast cancer is still not clear. This pilot study was undertaken to study whether there is any change in the management of breast cancer using WBPET scan in all patients of breast cancer irrespective of the stage? Materials and Methods: We retrospectively reviewed the data of 43 patients with invasive breast cancer who were newly diagnosed at Malignant Disease Treatment Centre at a tertiary care centre in East India. The duration of the study was between June 2020 and March 2021. Patients underwent liver function test, mammography, breast ultrasound, bone scan, and tru-cut needle biopsy to confirm the presence of breast cancer and 18F-fluoro-Dglucose (FDG) positron emission tomography/computed tomography (PET/CT) was studied in all 43 patients before the initiation of any therapy. The primary objective was to find out whether doing a WBPET upstaged the disease and changed our management. The secondary objective was to determine whether hormonal status (oestrogen receptor [ER], progesterone receptor [PR] and human epidermal growth factor receptor 2 [Her2] Neu) and Breast Imaging-Reporting and Database System (BIRADS) score staging had any correlation with metastasis. Results: A total of 43 patients with newly diagnosed breast cancer were studied. The number of patients in Stage IIA (3/43), Stage IIB (4/43), Stage III A (17/43), Stage IIIB (13/43), and Stage IV was (6/33). Out of total 43 patients, in 10 (23%) patients, there was a change in treatment on doing an upfront WBPET scan. There was no correlation between ER, PR, or Her2 Neu positivity or negativity on the upstaging of the disease and change in treatment. Standardised uptake value (SUV) uptake of the primary lesion >7.2 was associated with upstaging and change of treatment. Conclusion: The use of 18F-FDG PET/CT has been shown to bring change in treatment in almost 20% of patients with breast cancer. Although the role of other variables in breast cancer such as hormone status, SUV of the primary lesion, and grade of lesion on BIRADS has also shown some association with change of treatment.